Background: The Commission of Analytical Quality and the Committee of External Quality Programs of Spanish Society of Laboratory Medicine (SEQC) in collaboration with the Dutch Foundation for the Quality organized the first national category 1 External Quality Assessment Programs (EQAP) pilot study. The aim is to evaluate the standardization of serum creatinine measurements in the Spanish laboratories through a category 1 external quality assurance program with commutable material and reference method assigned values.
Methods: A total of 87 Spanish laboratories were involved in this program in 2015. Each day a sample control was measured by duplicate during 6 consecutive days. Percentage deviations and coefficients of variation obtained were compared with quality specifications derived from biological variation.
Results: A total of 1044 creatinine results were obtained. Laboratories were coded in 11 different method-traceability combinations. Only enzymatic methods get all results within the acceptability limits.
Discussion: To participate in a category 1 EQAP is a valuable tool to assess the standardization degree in our country; a big effort should be made to promote laboratories to change their procedures and to use enzymatic creatinine methods, in order to achieve a satisfactory standardization degree for this important analyte.
Keywords: Creatinine; commutability; external quality assessment programs (EQAP); standardization; traceability.